The basic encodings

1. geoshape:color showing severity of pandemic, opacity showing clicked data, tooltip giving additional information and can be combined with the click feature.
2. barchart: vertically country is ranked by daily new cases descending while keeping the top 10 only

Interactions

1. time slider feature: the user can use three sliders(year, month, day) to slide over the dataset that shows the aggregated daily new cases for each country.
2. interactive color changes: the color is a sequential color that shows a range between 0 to max(new cases), the sliding effect provide intuitive sense of how the pandemic is evolving.
3. clickable feature: user can click on a single country on the map or select the country from the top 10 bar chart; this will show the area with emphasis and at the same time make sure the user is clicking on the correct country when tooltip is providing additional information.

Some concerns

1. The african map has congo and congo demo republic; however, the covid dataset only has one set of data for congo. This caused a piece of the map missing in africa.
2. dealing with the log scale in color, very ineffective encoding with condition